All viruses, including SARS-CoV-2, the virus that causes COVID-19, change over time. Most changes have little to no impact on the virus’s properties. However, some changes may affect the virus’s properties, such as how easily it spreads, the associated disease severity, or the performance of vaccines, therapeutic medicines, diagnostic tools, or other public health and social measures.
In June 2020, the WHO Virus Evolution Working Group was established with a specific focus on SARS-CoV-2 variants, their phenotype and their impact on countermeasures. This later became the Technical Advisory Group on SARS-CoV-2 Virus Evolution. In late 2020, the emergence of variants that posed an increased risk to global public health prompted WHO to characterize some as variants of interest (VOIs) and variants of concern (VOCs) in order to prioritize global monitoring and research, and to inform and adjust the COVID-19 response. From May 2021 onwards, WHO began assigning simple, easy-to-say labels for key variants.
Considerable progress has been made in establishing and strengthening a global system to detect signals of potential VOIs or VOCs and rapidly assess the risk posed by SARS-CoV-2 variants to public health. It remains critical that these systems are maintained, and data are shared, according to good principles and in a timely fashion, as SARS-CoV-2 continues to circulate at high levels around the world. While monitoring the circulation of SARS-CoV-2 globally, it also remains essential to monitor their spread in animal populations and chronically infected individuals, which are crucial aspects of the global strategy to reduce the occurrence of mutations that have negative public health implications. In March 2023, WHO updated its tracking system and working definitions for variants of concern, variants of interest and variants under monitoring. They can be found here. The previous working definitions can be found here.
Statement on the update of WHO’s working definitions and tracking system for SARS-CoV-2 variants of concern and variants of interest
TAG-VE statement on the meeting of 3 January on the COVID-19 situation in China
TAG-VE statement on Omicron sublineages BQ.1 and XBB
Statement on Omicron sublineage BA.2
WHO announces simple, easy-to-say labels for SARS-CoV-2 Variants of Interest and Concern
Currently circulating variants of concern (VOCs) as of 15 March 2023
Note: To better reflect the current variant landscape, which is dominated by Omicron descendent lineages, WHO updated its tracking system and working definitions of VOCs and VOIs on 15 March 2023.
Recombinant of BA.2.10.1 and BA.2.75 sublineages, i.e. BJ.1 and BM.1.1.1
17-04-2023
XBB.1.16 Initial Risk Assessment, 17 April 2023
XBB.1.16 Updated Risk Assessment, 05 June 2023
XBB.1.9.2 + S:F456L
Includes EG.5.1: EG.5 + S:Q52H
09-08-2023
EG.5 Initial Risk Evaluation, 09 August 2023
EG.5 Updated Risk Evaluation, 21 September 2023
Currently circulating variants under monitoring (VUMs) (as of 17 August 2023)
Recombinant of BA.2.10.1 and BA.2.75 sublineages, i.e. BJ.1 and BM.1.1.1
XBB.1 + S:F486P (similar Spike genetic profile as XBB.1.5)
Recombinant of BA.2.10.1 and BA.2.75 sublineages, i.e. BJ.1 and BM.1.1.1
XBB.1 + S:F486P, S:Q613H
Recombinant of BA.2.10.1 and BA.2.75 sublineages, i.e. BJ.1 and BM.1.1.1
XBB + S:D253G, S:F486P, S:P521S
BA.2.86
(Only 3 sequences available. Added as VUM based on the large number of mutations identified)
* Excludes XBB sublineages listed here as VOIs and VUMs
# Excludes XBB.1.9.2 sublineages listed here as VOIs and VUMs
Technical Advisory Groups
Publications
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